I know you posted in the thread to FatOldFool, but I'd say send him a PM if you didn't already.
He's not as active as he used to be but said it was still available in Jan.
viewtopic.php?f=11&t=6246
That said, I don't think surface rust on the headers has truly detrimental impact on overall bike value. Most folks just want a bike that operates properly. As long as she purrs like a kitten, then I would just sell it as is.